Sine bar fixture



Sept. 26, 1944. A. A. BALK SINE BAR FIXTURE Filed Sept. 13, 1943 n nu HHInm I M IN VEN TOR. /748527 ,4 EALK M WE 7 27% slidin of the height gauge thereover.

Patented Sept. 26, 1944 UNITED STATES PATENT OFFICE 2,359,018 SINE BAR FIXTURE Albert .A. Balk, Garfield Heights, Ohio ApplicationSeptember 13, 1943, Serial No. 502,089 2 Claims. (01. 33-474) The present invention relates to sine bar instrumentsor fixtures used in inspection rooms, shops, etc., for checking angles, tapers and the like.

The principal object of the present invention is the provision of a novel and improved sine bar instrument or fixture which will be reliable in operation, simple in construction and convenient to use. I j

Other objects and advantages of the invention are the provision of a sine bar fixture so constructed and arranged that the moving parts will not wear excessively and'wherein the various parts can be adjusted relative to each other to correct any inaccuracies which may occur therein.

The invention "resides in certain details of construction and combinations and arrangements of parts and further objects and advantages thereof will be apparent to those skilled in the art to which the invention relates from the following description thereof described with reference to the accompanying drawing forming a part of this specification, in which similar reference characters designate corresponding parts, and in which Fig. 1 is a perspective view of a sine bar fix-' ture embodying the present invention; and

Fig. 2 is a rear elevational view of the sine bar fixture shown in Fig. 1.

The usual sine bar fixture comprises a surface plate, a height gauge, a sine bar and a set of thickness gauges. In practice, the height gauge and sine bar are placed upon the surface plate. The work piece to be checked is placed upon the sine bar and one end of the sine bar is raised by the thickness gauges until the angular surface or taper to be checked is determined by the height gauge to be horizontal or parallel with the working surface of the surface plate, after which the angle or amount of taper is determined from the sine of the angle as found by dividing the height as measuredby the thickness gauges by the length of the sine bar. Among the numerous disadvantages inherent in the aforesaid practice is the fact that the surface plate soon becomes worn and inactive due to the The wear referred to is increased by the fact that the base of the height gauge adheres to the surface plate and will not readily move thereabout. Other disadvantages are the fact that the various parts become disassembled and are not always readily available for use. According to the provisions of the present invention, the height gauge v or its equivalent is carried by a member slidably supported on parallel bars fixed to but preferably adjustable relative to the surfaceplate.

This construction overcomes many of the objections referred to above.

Referring to the drawing, the reference character A designates a base, preferably in the form by feet l0 fixed to the underside of the base or surface plate proper. The upper or working surface ll of the base or surface plate A is absolutely fiat and supports'the sine bar, designated generally by the reference character B, the righthand button ll of which, as viewed in the drawing, rests upon the surface H and is plvotally held in position thereon by a U-shaped bracket or sine bar clamp I3 which overlies the projecting end thereof. The sine bar clamp I3 is provided with a thumb screw M, the lower end of which is adapted to engage the top of the button [2. As shown, the bracket i3 is secured to the upper surface plate A by the screws I5, however, any other suitable arrangement could be employed. The opposite or left-hand end of the sine bar B is adapted to be raised by thickness gauges C resting, upon the working surface ll of the base A and engaging underneath the lefthand button I6 of the sine bar. The sine bar B shown is of commercial construction, is ten inches long and the buttons l2 and I6 are fixed to the ends of the bar proper. As shown, the sine bar B includes a U-shaped member I 1 engaging over the upper surface of the bar, which member constitutes a stop for holding vwork pieces placed thereon from sliding lengthwise of the bar when the free end is raised. The U.- shaped member or work clamp I! may be secured in any desired position along the sine bar by the clamp screw I9. I

In addition to the sine [bar B, the present instrument includes a member or carriage l8 for supporting a height gauge, designated generally by the reference character D. The height gauge D shown is of conventional construction and will not be described in detail. Suflice it to say that it comprises a vertical upright or indicator bar 2| secured to a base or indicator slide 20, sliding clamps 22 and 23 carried by the indicator bar 2| and a dial indicator 24 carried by an indicator bar 25 fixed to the lower clamp 23. The sliding clamps 22 and 23 provide means for adjusting the dial indicator 24 vertically and are provided with.

of the height gauge D is slidably secured in a groove 3| formed in the upper side of the member H "of sine bar .3 was raised by the thickness I3. The groove extends in a direction transversely of the sine bar B and the lower. surface thereof, upon which the indicator slide "rests is parallel or substantially parallel with the .surface ll of the surface plate A. The construction is such that the dial indicator 24 can be moved.

transversely of the sine bar B. Y

The member i8 which carries the height gauge D is slidably supported on two parallel bars 32 and 33 fixed to the base A. As shown, opposite ends of the bars 32 and 33 are connected to members 34 I and 35-flxed to the base A by means permitting adjustment thereof relative to the working surface ll. As shown, the members 34 and 35 are and held in place thereon by the U -shaped member ll and'the work rest 43. The left-hand end 32 and 33 can be readily set or their position the like formed in the ends of the member A so as gauge 24 travel in a plane parallel with the working surface I l of the surface plate A.

checked by causing the work engaging plunger SI of the dial indicator gauge 24 to engage ,the working surface ll of the surface plate A and by then moving the carriage I3 along the bars. Any necessary adjustment can be readily made by moving either or both of the members 34 and '35 in one direction or another. Because of the fact that it is not necessary to move the slide 20 of the height gauge D in the groove 3| of the carriage l3 any great amount, little, if any, wear occurs at this point.

From the foregoing description of the preferred embodiment of theinvention, it'will be apparent that the objects heretofore enumerated and others have been accomplished and that a new and improved sine bar fixture has been provided which is simple in construction, convenient and accurate in operation and in which the various parts can be adjusted to, eliminate any errors which may The parallel bars 32 and 33 are made of extremely hard material, ground and lapped, and ar subject to substantially no wear by the movement of the member or carriage l8 therealong. Obviously the parallel bars must be of sufllcient size so that they will not sag under the weight of the carriage l8 and the height gauge assembly D as they are moved therealong. In som instances, it may be desirable to operate the fixture with the carriage i8 located at one position for a, considerable period of time, in which event provision is made for supporting the weight of the carriage and height gauge assembly on the surface plate A in the form of an adjustable screw 33 threaded into a suitable tapped aperture in the underside of the carriage [8, the head or which screw is adapted to rest upon or engage the surface H of the surface plate A. I

The present invention also contemplates the provision of means for holding work uponthe sine bar B in the form of a work rest 40 slidablealong a work rest post 4| and adapted to be fixed in any position to which it might be moved therealong by a knurled thumb screw 33 threaded into a tapped aperture in the work rest 43, the inner end of which screw is adapted to engage the work rest post iii. The work rest post 4| is carried by a swivel nut 44 carried by the shank 45 of a T bolt, the head 35 of which is positioned in a T-' slot t! in the side of the surface plate A adjacent to and parallel with the sine bar B. The portion of the shank 35 of the T-bolt adjacent to the head 46 is enlarged and threaded and provided with a clamp nut 43 for fixedly securing th T- bolt in any desired position. The swivel nut 44 includes a clamping member 53 for fixedly securin; it in any adjusted position along the shank 43 of the T-bolt.

In Fig; 1 of the drawing, the sine bar fixture of'the present invention is shown as being employed to check the taper of a cone-shaped work piece W positioned upon the sine bar B arise therein. While the preferred embodiment of the invention has been described in considerable detail, I do not wish to be limited to the particular construction shown, which construc- 35 tion may be varied within the scope of this invention and it is my intention to hereby cover all adaptations, modifications and uses thereof which come within the practiceof those skilled in the art to which the invention relates and which 40 come within the spirit and scope-of the appended claims.

Having thus described my invention, what I claimis:

1. In a sine bar fixture of the character de- 4 scribed, the combination of a surface plate, a sine bar positioned on said surface plate, means for pivotally connecting one end of said sine bar relative to said surface plate, a plurality of parallel bars fixed to said surface plate, and a member '50 slidably supported on said bars and adapted to tive to said surface plate.

, scribed, the combination of a surface plate, a

sine bar positioned on said surface plate, means for pivotally connecting one end of said sine bar relative to said-surface plate, a plurality of parallel bars fixed to said surface plate, a member slidably supported on said bars and adapted to carry a height gauge, said bars extending in'a direction generally parallel to the projection of said sine bar upon the working surface of said surface plate and being so positioned that a height gauge supported on said member travels in a plane parallel to the surface of said surface piate upon said member being moved alon said bars, and means for adjusting said bars rela- ALBERT A. BALK. 

